Thread
My LC III wants to be a DJ.
When powered on, my LC III intermittently emits whining noises in varying tones through its speaker. I've swapped the speaker to no avail.
The kicker is that if I touch miscellaneous chips on the motherboard with varying degrees of pressure, I can alter the pitch and repetition rate of the whine.
Why is my LC III a beat machine?
The kicker is that if I touch miscellaneous chips on the motherboard with varying degrees of pressure, I can alter the pitch and repetition rate of the whine.
Why is my LC III a beat machine?
Beats me!Why is my LC III a beat machine?
My LC II and III both make whining noises which I assume are coming from the PSU which subside after a few minutes, I assume that they are merely going supersonic rather than actually abating.
You might wanna check. I assumed mine was the PSU as well, but it's definitely the speaker.
Once on, it goes quit every now and then only to start the whine again a few seconds later. Definitely not something that being powered on for a while cures.
Once on, it goes quit every now and then only to start the whine again a few seconds later. Definitely not something that being powered on for a while cures.
Could be noise on the power rails then. Do you have a similar machine you can swap components with to eliminate them from your inquiry? Eg swap PSU etc.
Nope. I run a tight ship nowadays.
Most likely it's bad capacitors on the logic board.
I have one that does this too from the speaker. It sounds like an old AM radio.
I have one that does this too from the speaker. It sounds like an old AM radio.
The board looks perfect, top and bottom. So I don't know.
Maybe my IIci spread a disease to it while they were in the closet together this past year...
Regardless, I'm more willing to screw with the LC III to keep it viable than I am the IIci. The LC III, majestically sitting next to a garbage can as I passed by on the walk home from school one day, won my heart and brought me over from the dark side.
Maybe my IIci spread a disease to it while they were in the closet together this past year...
Regardless, I'm more willing to screw with the LC III to keep it viable than I am the IIci. The LC III, majestically sitting next to a garbage can as I passed by on the walk home from school one day, won my heart and brought me over from the dark side.
I just got an LCIII from ebay and it has that whine/hiss/am radio noise too.
From my hardware background, I would think it was a failed capacitor too. I've noticed that while it oscillates audibly, the actual sounds going over the speaker (Apple Menu -> Control Panel -> Sounds, then clicking an alert sound like Quack) will be garbled. I would suspect the problem is isolated to the audio driver. Maybe something like a 555 Op Amp or a supporting capacitor.
Anyone isolate this further? If so, please post! I will post what I find.
From my hardware background, I would think it was a failed capacitor too. I've noticed that while it oscillates audibly, the actual sounds going over the speaker (Apple Menu -> Control Panel -> Sounds, then clicking an alert sound like Quack) will be garbled. I would suspect the problem is isolated to the audio driver. Maybe something like a 555 Op Amp or a supporting capacitor.
Anyone isolate this further? If so, please post! I will post what I find.
Don't we have twice the same problem here?
From what I understand, one could merge those two threads. Two of my pizza boxes (a LC and a LCIII) alsa wanted to become DJ's lately. It seemed to be some RF interference (from the AC board?) in the speaker. Does the noise stop when you plug in headphones?
From what I understand, one could merge those two threads. Two of my pizza boxes (a LC and a LCIII) alsa wanted to become DJ's lately. It seemed to be some RF interference (from the AC board?) in the speaker. Does the noise stop when you plug in headphones?